Preheat your oven to 350 degrees F and line a 9×13 inch baking pan with parchment.

To make the oat layer, combine all ingredients in a large bowl and stir to combine. Pour half of the mixture into the bottom of the baking pan and press the mixture down, spreading it evenly. Set aside the rest of the mixture.

In another large bowl, add the rest of the ingredients and stir to combine.

Pour the fruit mixture onto the crumble base and spread it out evenly.

Top the fruit with the rest of the oat mixture, spreading it out evenly.

Bake in the oven for 20 minutes. Let cool before slicing. Serve and enjoy!